We are very sad to say goodbye to Dr Lindsay Innes, OBE, FRSE who is retiring from the post of Book Review Editor that he has held for 15 years. During that time, Lindsay has worked tirelessly to ensure that regular readers of Experimental Agriculture have always been able to find out what books they should be reading, and why, by consulting the Journal's concise, incisive reviews by renowned experts from a bewildering range of fields. Lindsay, whose career description reads like a summary of all the top jobs in International Agricultural Research, always knew the best person to ask to review a book and the result was that we got the best reviews. We will miss him but we thank him sincerely for his work for the journal and we wish Lindsay the best of luck for the future.

Correct placement of side dress nitrogen (N) fertilizer could increase nitrogen use efficiency (NUE) and maize yield production. Field studies were established to evaluate application of midseason (V8 to V10), variable liquid urea ammonia nitrate (28%), N rates (0, 45, 90 and 134 kg N ha−1) and different application distances (0, 10, 20 and 30 cm) away from the maize row on grain yield and NUE at Haskell and Hennessey in 2009, Efaw in 2010 and Lake Carl Blackwell, Oklahoma in 2009 and 2010. A randomized complete block design with three replications was used throughout the study. Results indicated that maize grain yield in sites with adequate rainfall increased significantly (p < 0.05) with N rate, and poor N response was recorded in sites with low rainfall. Across sites and seasons, varying side dress N application distance away from the maize row did not significantly (p < 0.05) influence maize grain yield and NUE even with no prep-plant applied. Environments with adequate rainfall distribution had better maize grain yields when high side dress N rates (90 and 134 kg N ha−1) were applied 0 to 10 cm, and a higher NUE when 45 kg N ha−1 was applied 0 to 20 cm away from the maize row. For low N rates (45 kg N ha−1), increased maize grain yield and NUE were achieved when side dress N was applied 0 to 20 cm away from the maize row at locations with low rainfall distribution. Across sites and seasons, increasing side dress N to 134 kg N ha−1 contributed to a general decline in mean NUE to as low as 4%, 35%, 10%, 51% at Hennessey, Efaw, LCB (2009) and LCB (2010) respectively.

Cotton–wheat (CW) is the second most important cropping system after rice–wheat in South Asia. Sowing of wheat after cotton is usually delayed due to late pickings coupled with time needed for seedbed preparation, resulting in low wheat yield. Lack of suitable machinery is a major constraint to direct drilling of wheat into the heavy cotton stubbles. An innovative approach with much promise is the ‘2-wheel tractor-based self-propelled relay seeder’ with seed-cum-fertilizer attachment. On-farm trials were conducted at four locations during 2009–2010 and at 10 locations during 2010–2011 to evaluate the following four wheat establishment methods in CW-dominated areas of south-western Punjab, India: (1) zero till seeding in standing cotton using a self-propelled relay seeder, (2) relay seeding in standing cotton with a manual drill without prior tillage (2010 only), (3) relay broadcast seeding in standing cotton following light manual tillage and (4) conventional sowing of wheat after cotton harvest (conventional tillage and sowing with a seed–fertilizer drill). Planting of wheat under conventional practice was delayed by 20–44 days compared with relay seeding. Seed cotton yield was also significantly higher with relay seeding due to opportunity for one additional picking. Yield of wheat sown with the self-propelled relay seeder was 41.2% and 11.8% higher than with conventional practice in 2009–2010 and 2010–2011 respectively. The increase in wheat yield under relay seeding of wheat was primarily due to higher spike density and more grains per spike. The net income from the CW system was 28.2% higher for the self-propelled relay seeder than with conventional sowing.

The physiological performance of four cacao clones was examined under three artificial shade regimes over the course of a year in Ghana. Plants under light shade had significantly higher photosynthetic rates in the rainy seasons whereas in the dry season there was a trend of higher photosynthetic rates under heavy shade. The results imply that during the wet seasons light was the main limiting factor to photosynthesis whereas in the dry season vapour pressure deficit was the major factor limiting photosynthesis through stomatal regulation. Leaf area was generally lower under heavier shade but the difference between shade treatments varied between clones. Such differences in leaf area allocation appeared to underlie genotypic differences in final biomass production in response to shade. The results suggest that shade for young cacao should be provided based on the current ambient environment and genotype.

Ten endophytic bacteria were isolated from different sugarcane varieties growing in the Crop Research Centre, Pantnagar on nitrogen-free medium. Plant growth-promoting potential of the isolates was reported in terms of indole acetic acid (IAA) production, phosphorus solubilization, siderophore production and antagonistic action against the pathogen Colletotrichum falcatum, which causes red rot disease in sugarcane in vitro. All the isolates were able to produce IAA (4.8–9 μg ml−1); three isolates (H3, H5 and H14) solubilized insoluble phosphorus on Pikovaskaya's agar; two isolates (H10 and H14) showed siderophore production on Chrome-azurol S (CAS) agar and antagonism against C. falcatum was exhibited by two isolates (H14 and H15) in a dual plate assay. 16 S rRNA sequencing identified isolates H3 and H12 as Pseudomonas spp., and H8, H14 and H15 as Bacillus spp. A field experiment on sugarcane was conducted with five plant growth-promoting bacterial endophytes Pseudomonas spp. (H3 and H12) and Bacillus spp. (H8, H14 and H15) along with standard strains of Gluconacetobacter and Azospirillum spp. Plant height, chlorophyll content, total nitrogen and cane length were significantly higher in almost all inoculated plants compared with the uninoculated control. An increase of 40% in cane yield over the control was obtained after inoculation with isolate H15 (Bacillus spp.). This was statistically on par with the standard endophyte Gluconacetobacter diazotrophicus, which resulted in 42% increased cane yield. Identification of new diazotrophs and their promising results towards improving plant growth in the field suggest their use as inoculants in future.

High temperature stress at flowering can adversely affect rice yield, largely due to failure of fertilization. Oxidative damage can be a major reason inducing spikelet sterility in rice. In the present study, the effect of high temperatures on antioxidant metabolism in rice spikelets was characterised using nine different genotypes. Exposure to different temperatures at flowering stage revealed significant differences among various antioxidant enzymes in spikelets, both quantitatively and qualitatively. Spikelets of susceptible genotypes withstood temperature stress of up to 35 °C, those of moderately tolerant between 35 °C and 38 °C and those of tolerant genotypes up to 40 °C. Presence or absence, and changes in the isozyme intensities were consistent with alterations in their activities. Superoxide dismutase (SOD) isozymes II and III were present after exposure at 30 °C and 35 °C, while SOD I appeared above 40°C. Intensities of catalase isozymes I and III and the only isozyme of ascorbate peroxidase altered, while the only isozyme of guaical peroxidase and two (III and IV) of the four isozymes of catechol peroxidase disappeared after high temperature exposure of 45 °C. Thus, this work provides an evidence of the role of antioxidant metabolism in spikelets under high temperature stress conditions. Hence, changes in antioxidant isozymes in rice spikelets can be used as a biomarker for characterizing high temperature stress tolerance in rice spikelets.

The macadamia nut is the only commercial food crop indigenous to Australia. It originated along the fringes of rainforests, only becoming an important internationally traded crop in the late 20th century. Australia is now the main centre of production, following a lead set by Hawai'i. The crop is also important in Central America and southern Africa. The majority of recent research reported in the literature on the physiology and water relations of macadamia has been undertaken in Australia. Macadamia is a tall evergreen tree in which vegetative growth occurs in a series of flushes. Mild water stress suppresses growth, but compensatory growth occurs on re-watering. Flowers form on hardened wood within the leaf canopy. Floral initiation occurs in late autumn, with flowering in the following spring. Flowering is profuse but only 5–10% of the flowers set fruit and less than 1% of the flowers reach maturity as fruits due largely to premature abscission. High temperatures (>30 °C) can contribute to the shedding of fruit. It takes about 12 months from floral initiation to the completion of harvest. Macadamia root systems are described as relatively shallow and spreading. The taproot can extend to depths of >1.2 m, with a dense matt of fibrous roots in the top 0.4 m. Proteoid rootlets are also present. Stomata are only found on the abaxial surface of the leaf. Macadamia has several attributes that help to explain its apparent tolerance to periodic dry conditions as found in its native habitat. These include leaves with xeromorphic adaptations, stomatal closure without concurrent changes in leaf water potential and an efficient water transport system. There has only been one serious attempt to measure the actual water use of macadamia. Most irrigation experiments have been poorly planned and/or the outcomes were inconclusive. Nut yields are cyclical and highly variable, making it difficult to establish cause and effect. It is not yet possible to say with evidence where and when irrigation is worthwhile.

Date palm is a crop suited to hot, arid regions. It originated in Mesopotamia and the centres of production are in West Asia and North Africa. Despite its regional and international importance, and its dependence on irrigation or a shallow water table for survival, relatively little research has been published on the water relations and irrigation need of date palm. Following early work in California, the majority of the recent research reported in the literature has been conducted in Saudi Arabia and Tunisia. The date palm has a terminal crown of 100–120 leaves. At the base of each leaf is an axillary bud, most of which develop in the winter as flower buds. It takes 150–200 days from pollination to fruit maturity. Stomata occur on both leaf surfaces. Different techniques have been used to measure the water use of date palm, including micrometeorological and sap flow methods. In Syria, mean actual evapotranspiration rates varied between 0.5 mm d−1 (winter) and 3.5 mm d−1 (summer), in Saudi Arabia from 2–3 to 8–11 mm d−1 depending on location and in Jordan from 2 to 8–10 mm d−1 respectively. In Tunisia, there was some (limited) evidence of stomatal control of transpiration rates (seasonal range 0.5 to 3.5 mm d−1) when temperatures exceeded 32 °C. Experimentally determined values of the crop coefficient were inconsistent, varying from 0.6–0.7 to 1.18. In the vicinity of an oasis, advection may increase potential water use substantially above that of a reference crop. In the absence of a shallow water table, roots can extract water from soil depths greater than 2 m. There is little published information on the water productivity of date palm. A target benchmark figure is probably about 1.3-kg fresh fruit m−3 of irrigation water applied. Under controlled conditions, phenotypes differed in their responses to water stress. The date palm is traditionally considered to be relatively salt-tolerant, with a threshold electrical conductivity value for the saturated soil extract of 4.0 dS m−1, but recent evidence from Israel suggests that this view may be mistaken. Since early times, flood irrigation has been used to irrigate date palm and it is still probably the most common method in many countries. Since the 1980s, farmers have been encouraged by governments to use localised irrigation methods (e.g. micro-sprinklers, drip and bubbler) as a means of saving water. Since water is a scarce resource in the West Asia and North Africa region, research should focus on developing ways to improve the water productivity of this high value crop.

This paper explores changes in the organization of seed supply in China over the last decade by means of a multi-level institutional analysis. At the landscape level, the implications for China of the regulation of plant genetic resources through various international treaties and conventions are reviewed in the light of the evolution of the global seed industry. At the regime level, the transition in the Chinese context to market-based seed supply and the development of commercial and public seed sectors are examined. The study then analyses trends in seed supply at the niche level, with reference to participatory maize (Zea mays L.) breeding in three provinces in southwest China where high rural poverty persists. This work offers radical novelty in variety development and seed provision on behalf of smallholder farmers. However, a series of technical, organizational and market ‘mismatches’ are demonstrated within the existing seed regime. The participatory work emphasizes breeding for diverse cultivars adapted to specific ecosystems but these are prevented from reaching commercial markets by existing varietal testing procedures. Participatory breeding has potential to address farmers’ varietal needs as agriculture modernises and to support the public function of research institutes, but within mainstream intellectual property regimes the public value of participatory breeding cannot be accommodated adequately. Yet, when coupled to institutional innovations for recognising intellectual property and sharing benefit among all those who contribute, participatory breeding may initiate a powerful dynamics for change within seed regimes and a sui generis seed system suited to the Chinese context.

Farm households in the Andean region of South America face serious livelihood challenges, including a poor natural resource base and declining agricultural yields. Conservation agriculture has been identified as a potential solution to environmental degradation and the associated poverty and food insecurity in the region. This study analyses the potential economic impact of conservation agriculture in two sub-watersheds in central Ecuador utilizing a linear programming model and data from experiments in farmer fields. The model found that specific cover crops, crop rotations and reduced tillage designed to reduce soil erosion and increase soil organic matter can lead to increased incomes for farm households in a time period of as short as two years. It appears that conservation agriculture practices have the potential to improve the livelihoods of the rural poor in Ecuador because conservation agriculture activities entered the revenue-maximizing model solution for both sub-watersheds.